Single-trigger device



July 8, 1941.

SINGLE-TRIGGER DEVI CE Filed July 23, 1938 4 Sheets-Sheet 1 L EFT HAMMER Q LE FT SEAR Jade/r m W T y 1941- F. 'r. FAHLEN 2,248,858

SINGLE-TRIGGER DEVICE v ARC an IDLE I'redmpick ZKFahZe/n/ Patented July 8, 1941 UNITED STATES PATENT OFFICE SINGLE-TRIGGER DEVICE Frederick T. Fahlen, Phoenix, Ariz.

Application July 23, 1938, Serial No. 220,972

12 Claims.

This invention relates to improvements in fire arms, more particularly in the trigger mechanism of small fire arms such as shot guns of both the over-and-under and parallel horizontal barrel types. The instant description is to be regarded as concerned with a shot gun of the latter type, but in principle the invention is applicable to a gun of the former type as especially brought out in a co-pending application for patent for Twin single-trigger devices, by Frederick T. Fahlen, filed March 30, 1938, Serial No. 198,996. Note is also made of an application for patent for Single-trigger devices, filed by Frederick T. Fahlen, October 22, 1936, Serial No. 107,071.

Each of the foregoing applications lays emphasis on the use of a so-called floating auxiliary sear, the underlying purpose of which is to actuate the second main sear of a twin-sear firing mechanism upon the secondary voluntary depression of a selected trigger, doing this with a facility superior to the same accomplishment in known types of guns because of an improved lever action, and what is of utmost importance making the second depression of the selected trigger an entirely voluntary act, immune from the effect of the involuntary and unpreventable vibration of the trigger due to the recoil of the gun after the first shot. The latter principle is announced in the second application with particular force because of a more adequate provision for the occurrence of a conveniently termed arc of idle motion, the idea being that the involuntary'vibration of the trigger after the first shot can spend itself in a neutral zone, defending the second shell, so to speak, from being fired until the shooter so intends.

Speaking more directly in reference to the instant disclosure, it will be recognized in the following description that the invention is mainly concerned with refinements of structure and not with any chang whatsoever of the foregoing principles. With this preamble in mind, the objects of the invention are as follow:

First, to definitely defer the functioning of the single-trigger mechanism during the period of first pull of the selected trigger and during the immediately succeeding period of relaxation and involuntary second pull of said trigger, this function being accomplished by the intervention of a projection on the trigger blade.

Second, to fit out a gun of any known type, the instant gun being a Winchester shot gun, with a single-trigger device without having to change the structure or action of the safety device originally in the gun and without either inletting the gun stock to more than an immaterial degree, or mutilating the existing mechanism except to an extremely small degree as later brought out, and particularly preserving one of the original purposes of the safety device as a resetting instrumentality.

Third, to provide a single-trigger device which has been simplified in construction to the point of actually encouraging the installation ofthe invention in known types of guns because of the ability to make the few parts by simple machine processes with an attendant low cost.

Fourth, to introduce a change in structure in the trigger, said change being in furtherance of the functioning of the single-trigger device, and when once installed in a gun lending itself to the working of the normal firing mechanism as in any known gun even in the event of the singletrigger device being removed from the gun for any purpose whatsoever.

Fifth, to improve the mode of advancing the auxiliary sear so as not only to keep it under moving tension, but also to stabilize its action.

Other objects and advantages will appear .in the following specification, reference being had to the accompanying drawings in which,

Figure 1 is a combined sectional and elevational view of a portion of a Winchester gun receiver, showing the single-trigger device in the initial and cocked position of the hammers, also illustrating the use of the safety lever rod as a resetting instrumentality.

Figure 2 is a similar View illustrating the change in position of the parts following the first intentional pull of a selected (the left) trigger.

Figure 3 is a similar view illustrating the change in position of the parts after the release of the selected trigger.

Figure 4 is a similar view' illustrating the change in position of the parts following the second intentional pull of the selected trigger.

Figure 5 is a horizontal section taken on the line 55 of Figure 4.

Figure 6 is a perspective view of the auxiliary sear.

Figure 7 is a perspective view of the latch which works in conjunction with the sear.

Figure 8 is a view similar to Figure 1 illustrating a modified form of the single-trigger device, and distinguishing from the former by hav--, ing the latch pivoted to the auxiliary sear instead of independently thereof.

Figure 9 is a view corresponding to Figure .2 illustrating the change in position of the parts following the first intentional pull of the selected trigger.

Figure 10 is a view corresponding to Figure 3 illustrating the parts in position after the release of the selected trigger.

Figure 11 is a view corresponding to Figur 4 illustrating the parts in the position of the parts following the second intentional pull of the selected trigger. V

Figure 12 is a horizontal section taken on the line I2I2 of Figure 11.

Figure 13 is a perspective view of the auxiliary sear.

Figure 14 is a perspective view of the latch which works in conjunction with the auxiliary sear.

Figure 15 is a perspective view of the push block.

Figure 16 is a perspective view of the push block mount.

Attention is first directed to Figs. 1 to 7 which illustrate the first form of the invention wherein the latch is pivoted to the trigger plate as distinguished from the second form of the invention in Figs. 8 to 16 wherein the latch is pivoted to the auxiliary sear. The receiver, generally designated I, has right and left hammers 2, 3 embodied in it, these being held back in their cocked positions by right and left main sears 4, 5. These sears are movable against the tension of springs (not shown) by the depression of the respective right and left triggers 6, I.

The previously mentioned springs for actuating the hammers 2, 3 are engaged with notches 8 in portions thereof, these notches being substantially diametrically opposed to bottom shoulders 9 with which the main sears are engaged to hold the hammers in their cocked positions. The triggers 6, 1 are mounted upon a common pivot II] which is held in a mount II which is functionally integral with the trigger plate I2. The triggers 6, I include blades I3, I4 which work in slots I5 in the foregoing mount I I (Figs. 3, 4 and 5). These blades also work in slots, and necessarily so, in the trigger plate I2 as well shown in the drawings. The right and left trigger blades have heels I6, II.

A hole I8 in the mount I I contains a portion of and guides the rod I9 of the safety lever 20. The rod and lever are pivoted together at 2|, and the lever is pivoted at 22 to a portion of the trigger plate I2 as later explained. The lever is operable by a finger piece (not shown) on top of the receiver I. This finger piece is subject both to automatic and manual operation, the first act moving the finger piece backward to carry the lever 20 to the dotted line safety position (Fig. 1), the second act moving the finger piece forwardly to stand the lever in the full line ofi-safety position, but operative position of the gun.

The rod I9 carries a depending lug 29. The normal purpose of this lug is to obstruct triggers when the lever 2!] is in the safety position (dotted lines, Fig. 1) An additional and quite important purpose of the lug in its new combination as herein disclosed is to empoly it as a means for resetting the single-trigger device.

Reverting to the main sears 4, 5, these are commonly pivoted at 32 to the receive I. They extend backward beside the mount I I (Fig. 5), and terminate in inwardly directed fingers 33, 34. Thus far the description has been generally common to application Serial No. 107,071 and in general agreement with the structure of known guns of the instant type.

Each of the triggers 6, I is substantially alike in construction, the main exception being that the left trigger I is longest (Fig. 1). The previously mentioned improvement to the trigger blade, referring now to the left trigger blade I4, comprises the backward elongation of the heel I! toform a projection 30. The backward extent and height of this projection are matters for determination and change as required in reducing the invention to practice, but it is important to observe that the height of the projection is of a considerable dimension because its back edge is a component of the parts which produce an arc of idle motion (Fig, 2).

In the Winchester gun illustrated, and possibly in other guns, it may be necessary and is generally desirable to increase the vertical dimension of the trigger blade in order to provide adequate trigger play for an ample degree of arc of idle motion. This is accomplished in the particular instance indicated in the drawings by cutting the ledge 3| back substantially from the dot and dash line (Fig. 1).

Reference is now made to the auxiliary sear generally designated 35 (Fig. 6). This consists of a body 36 from the lower portion of which a pair of arms 38, 39 extend. These arms taper as shown and underlie the inwardly directed fingers 33, 34 of the main sears. These arms have upturned terminals 40, 4|, hereinafter termed latch abutments.

Said arms 38, 39 are connected by a bridge 42, the latter establishing the spacing of the arms so that they are properly distanced to lie outside of the trigger blades I3, I4 (Fig, 5). The forward portions 43, 44 of the bridge 42 comprise shoulders which are functionally identical with correspondingly shouldered portions of the auxiliary sear in application Serial No. 107,071. The bridge 42 has a projection 45, comprising a prong to be engaged by the lug 29 in the resetting act of the auxiliary sear. Reverting to the latch abutments 4|), 4|, it is to be observed that these are rather fully rounded at 46 at their points of mergence with the respective arms, these rounded portions comprising the fulcrums for leverage which is described later.

A latch 52 (Fig. 7) tends to prevent movement of the auxiliary sear 35. This latch comprises a thin central web 53 which is situated between the trigger blades I3, I4 (Fig. 5). At its forwardend this web has an enlargement 54 which is surmounted by a head 55 which is abuttable by at least one of the latch abutments 4!), 4| of the auxiliary sear 35. However, according to the present showing the head 55 is extended on each side of the enlargement 54 so as to be engaged by both latch abutments in the initial position of the single-trigger device (Fig. 1).

The enlargement 54 carries a pair of concentric pins 56, 51 which overlie the trigger blades I3, I4 (Fig. 5). At its rear terminal the central web 53 is expanded at 58 into the form of a loop, the side arms 59 of which have holes 6!] for the reception of the previously described pivot 22. The bridge piece 6| of the loop is offset upwardly from the side arms and has a centralized pin 62, or its equivalent, to retain the upper end of a spring 63 which is seated in a recess 64 in the trigger plate I2.

The pivot 22 is long enough to extend beyond the sides of a push block mount 65 and occupy the holes 6|] of the loop 58. It is thus that the latch 52 is mounted upon the trigger plate in a relatively stationary position, as distinguished from the mount of an equivalent latch on the auxiliary sear as is described in conjunction with the second form of the invention in Figs. 8 to 16. The mount 65 is functionally integral with the trigger plate I2. The safety lever 20 is situated centrally of the mount, the latter being divided at 66 for the purpose.

Said mount is recessed at 61 to make room for a push block 68 (Fig. 15). This push block has a central passage 69 clearing the way for the lever 20. The resulting'members 10 are bored at H for the occupancy of the forward ends of springs 12 (Fig. said ends being seated upon shoulders formed by counter bores 13. These counter bores receive guide pins 14 which project forwardly from the upright walls of the recess 61. The rear ends of the springs 12 are seated upon these walls around the bases of the guide pins. An apron 15, depending from the block 68, is initially and incidentally engaged with the mount 65, its primary purpose being to extend the area of engagement of the forward beveled face 16 of the push lblOCk 68 with the rear of the body 35 of the auxiliary sear 35.

In the initial position of the parts (Fig. 1) the tips of the guide pins 14 project beyond the face 16, by virtue of the fact that the block 68 is in its farthest back position, said projecting tips overlying the bridge 42 of the auxiliary sear 35 to keep it from being lifted by the first pull of the selected trigger. Before going on to the description of the modification of the single-trigger device, attention is again directed to the lug 29 which depends from the safety lever rod l9. Inasmuch as this lug is directly over the pins 56 of the latch 52 in the forward position of the safety lever rod it becomes necessary to notch the lug at 11 (Fig. 1) in order to make room for said pins when the latch is raised (Fig. 2). On the same principle the forward surface of the lug is undercut at 18 to accommodate the latch enlargement 54.

' Attention is now directed to the modification in Figs. 8 to 16. It will be noticed that much of the basic structure is identical in the two forms of the invention. This being true, such parts as are the same are designated by corresponding numerals without describing the details, but distinguishing the modification by the exponent letter 0,.

Those parts of the modification which involve diiferences in structure from the first form, are described as follows: The auxiliary sear 35 (Fig. 13) has the arms 38 39 lengthened and tapered so that their fulcrum points 46 are situated more closely to the sear pivot 32 than are the fulcrum points 46 of the auxiliary sear 35 (Fig. 6). These arms 38*, 39 now underlie the sears 4 5? in distinction to the equivalent arms 38, 39 (Fig. 5) underlying the sear fingers 33, 34.

Reverting to Figure 13, the body 36 of the auxiliary sear also terminates in shoulders 43*, 44 these being produced by a slotting of the body at 79. Matching holes 66 in the shoulders 43*, 44 contain the ends of a pin 8| which provides the pivotal mount for the latch 52 (Fig. 14) which occupies and works in a longitudinal slot 82. This latch is much on the order of the latch 52 as will be seen. The head 55 is shown in single form, and in this instance is adapted to initially engage a back edge of at least one of the trigger blades (Figs. 8 and 12). The latch includes a standard 83 (Fig; 14) which is turned horizontally at 84, a pair of lateral projections 85, 86 being situated at the turn, these being the equivalents of the concentric pins 56, 51 of the latch 52 (Fig. '7) A hole 87 (Fig. 14) in the portion 84 contains the center of the pin 8|. A depending pin 88 provides the mount for one end of the spring 89 which is seated in a recess 90 in the bridge 42 (Figs. and 11) of the auxiliary sear 35 Respecting the latch 52, 52 in each of the tWo forms of the invention, it is observed that the general configuration provides a well defined central depression 9|, 9W the purpose of which is to avoid in all positions the depending lug 29, 29* of the safety lever rod.

The operation is readily understood. The act of cooking the gun automatically carries back the safety lever rod l9, l9 which in turn moves the single-trigger device into a latched and inoperative position (Figs. 1 and 8). Attention is first directed to the first form of the invention. Figure 1 shows the single-trigger device in'the previously mentioned latched position. It is to be borne in mind that the sole function of the auxiliary sear 35 (Fig. 6) is to actuate themain sear of the second gun barrel upon the second voluntary depression of a selected trigger. Bearing this purpose in mind the function of the latch 52 (Fig. 7) will be fully comprehended because of the obstructing position which the head 55 occupies in advance of the latch abutments 40, 4|.

The springs 12 exert constant tension on the auxiliary sear through the intermediate push block 68. In this description the left trigger 7 is selected for firing the gun. But it is to be understood that sequences identical with the following would occur were the selection the right trigger.

In Figure 2 the selected left trigger I has been given the first pull (arrow a). It is important to observe that the trigger projection 30 rises to an altitude within range (arrow 17) of the shoulder 44 and at the same time the left sear 5 is turned (arrow 0') to release the left hammer 3 prior to the displacement of the latch head 55 from its obstructing position in front of the latch abutment 4i. Continued pressure on the left trigger I during its initial pull elevates the latch head 55 beyond the abutment 4|; (arrow 12, Fig. 2) this because of the pressure of the trigger blade l3 against the pin 51 (arrow e).

The trigger projection 30 now occupies what has been termed an arc of idle motion (Fig. 2), the approximate extent of permissible and involuntary vibration being clearly designated by the full and dotted line positions of said projection. At this point the reader will understand that the gun recoils following the firing of the first shell by the release of the hammer 3 causing the shooters finger to produce what in effect comprises a second involuntary pull.

It is readily seen that if this involuntary act can be dissipated, regardless of how extensive it might ordinarily be within reasonable limits, the firing of the second shell will be avoided. Now the-purpose and effect of the designated arc of idle motion can be clearly understood. The trigger projection 30 can move up and down in the neutral zone but will not leave its obstructing position in front of the auxiliary sear shoulder 44 and consequently will hold .the latter back until the shooter voluntarily lets the trigger down to its normal position (Fig. 3).

The auxiliary sear 35 now advances (arrow f,

' Fig. 3). It does so because of the spring pressure behind the engaging push block 68 and further because of the latch head 55 being out of theway. Prior to this time the auxiliary sear 35 has been in an inoperative position insofar as the performance of its sole purpose in actuating the right sear 4 is concerned. Observe in Figure 3 that the combined voluntary relaxation of the trigger 1 and the forward advance of the auxiliary sear has superimposed the shoulder 44 upon the trigger projection 30. This superimposition and resulting interengagement will presently be responsible for the tilting of the auxiliary sear when the left trigger is given its second voluntary pull.

Figure 4 illustrates the latter act. The second pull of the left trigger (arrow g) produces a lifting motion upon the shoulder 44 (arrow h), turning the auxiliary sear on its fulcrum 46 and causing its right arm 38 to elevate the right sear finger 33 with a lever-like action. The left sear 5 is lifted again by the left arm 39 of the auxiliary sear but inasmuch as the left barrel has been fired this repeated turning of the left sear is idle. The consequent turning of the right sear 4 (arrow 2', Fig. 4) releases the right hammer 2 and causes the firing of the shell of the right barrel. Although the latch 52 is raised a second time (Fig. l) by virtue of .the second lifting of the pin 51 by the left trigger blade 14 said raising comprises a functionless act.

Reference is next made to the modification in Figs. 8 to 16. The sequences of operation in Figs. 8 to 11 are identical to those in Figs. 1 to 4. The only differences in operation concerns the latch 52 In Figs. 8 to 11 the latch is carried by the auxiliary sear 35 consequently is subject to the floating quality of the latter. In Figs. 1 and 4 the latch 52 is mounted independently of the auxiliary sear 35, and the motions of the latter are not imparted to the latch.

In Figure 8 the latch 52 holds the auxiliary sear 3511 out of range of action of the projection 30 of the selected trigger 1 against the tension of the spring and the push block 58 because of the head 55 being stationed in back of an upright edge of the trigger blade M When the left trigger I is pulled the first time (arrow 7', Fig. 9) the projection 3H enters the zone of the arc of idle motion in front of the shoulders 43*, 44 and the left sear 5 is swung to the left hammer releasing position prior to the elevation of the head 55 above the left trigger blade.

The left trigger I having been released (Fig. 10) an advance of the auxiliary sear 35 occurs because of the ability of the head 55 to ride on top of the blade M The auxiliary sear arms, more particularly the arms 3B (Fig. 13), are slipped slightly farther under the sear fingers, particularly the finger 33 (Fig. 12) Actual contact is not necessarily made. Inasmuch as the sear shoulder 44 has become superimposed upon the trigger projection t0 (Fig. 10) because of the advance of the auxiliary sear, it follows that the second pull of the left trigger (arrow 1c, Fig. 11) is responded to by a tilting of the auxiliary sear on its fulcrum point 46 The right sear 4 is turned (arrow 1, Fig. 11) releasing the right hammer 2 for the firing of the shell in the right barrel.

In each of the two forms of the invention (Figs. 1 and 8), the projecting tips of the pins 14, M hold the respective auxiliary sears down against inadvertent raising movement upon the first pull of the selected trigger, it being remembered that in each instance the auxiliary sear is in free floating relationship to the firing mechanism, being sustained in its operative relationship therewith solely by frictional contacts and not by any aflixation. The projecting pin tips are thus stabilizing factors, the function of stabilization being transferred to the push block 58, 68 in the subsequent sequences during which said pin tips are sequestered in the push block, because of the natural bearing down function that the forwardly beveled face 16 has upon the head of the auxiliary sear.

I claim:

1. In a double-trigger, double-barreled fire arm having a pressure actuated hammer for each barrel and a pivoted sear to hold each hammer in a cooked position, a single-trigger device comprising a body, arms projecting from said body, means connecting the arms and forming a shoulder, said arms having fulcrum points initially partially disposed beneath the sears, latch means contacting a part of the body to initially hold the shoulder away from the trigger blade, a spring constantly tending to push the singletrigger device into a position of engagement of the shoulder with said trigger blade, and a movable push block constantly held against the body, being an intermediary between the spring and said device, transmitting the spring-push after the first pull of one of the triggers by which pull one of the sears is lifted thereupon to move said device so as to bring the shoulder within engaging range of the trigger blade and the fulcrum points of said arms farther under the sears and closer to the pivots thereof, preparatory to a lever-action upon both sears through the initial operation of the single-trigger device by a second pull of said onetrigger.

2. In a fire arm having selectible triggers, each with a blade, and hammer sears correlated with the respective blades, a trigger plate adjacently to which said blades are pivoted, a single-trigger device riding upon said plate but being in floating relationship to said blades, said device having arms individually alined with the hammer sears and including fulcrum points initially partially disposed beneath the scars, a body connecting the arms and providing a shoulder confronting a trigger blade, a spring constantly tending to push the single-trigger device into a position of engagement of the shoulder with said triggerblade, a push block between the spring and body, and means embodied in the push block, being in immediate and constant contact With the body, comprising a formation exercising a bearing down action on the single-trigger device, keeping it down against the trigger plate.

3. In a fire arm having selectible triggers, each with a blade, and hammer sears correlated with the respective blades, a trigger plate adjacently to which said blades are pivoted, a single-trigger device riding upon said plate but being in fioating relationship to said blades, arms individually aligned with the hammer sears, being a part of said device, and having fulcrum points initially partially disposed beneath the scars, a body connecting said arms and providing a shoulder, a spring constantly tending to push the singletrigger device into a position of engagement of the shoulder with said trigger-blade, and a push block upon which the spring acts directly, said push block having a beveled face constantly bearing against the body of the single-trigger device, urging and keeping it down against the trigger plate.

4. In a double-barreled fire arm having hammers for the respective barrels, sears to hold the hammers cocked, and a selected trigger to be initially pulled to actuate one hammer sear, a loosely emplaced auxiliary sear having arms individually in underlying relationship to the hammer sears, a bridge connecting the arms, adapted to sequester a portion of the selected trigger and defining a shoulder engageable by said trigger portion and tending constantly to hold the loose auxiliary sear down and the bridge in line for engagement by said trigger portion, a spring tending to move the auxiliary sear into the sequestering position of its shoulder structure, and a push block upon which the spring acts directly, said push block having a beveled face bearing against a portion of said shoulder structure, moving said auxiliary sear after the first pull of the selected trigger to bring the shoulder structure into contact With said portion of the respective trigger to postpone the further movement of said auxiliary scar and permit said trigger to vibrate in an arc of idle motion defined by the extent of contact of said structure and trigger portion until the pull on the selected trigger is voluntarily relaxed.

5. In a double-barreled fire arm having hammers for the respective barrel, hammer sears to hold the hammers cocked, and a selected trigger to be first intentionally pulled to actuate one hammer sear, release the respective hammer and fire the respective barrel, said trigger having a blade with a projection, an auxiliary sear having arms in underlying relationship to the hammer sears, a shoulder structure connecting the arms and forming a bridge adapted to sequester said projection, a latch engaging a part of the auxiliary sear to hold the shoulder structure away from said projection, said latch being displaced upon said first pull of the trigger, a spring then moving the auxiliary sear to abut the shoulder structure with said projection, and a push block upon which the spring acts directly, said push block having a beveled face bearing against said shoulder structure.

6. In a double-barreled fire arm having hammers for the respective barrels, hammer sears to hold the hammers cooked, and a selected trigger to be first intentionally pulled to actuate one hammer sear, release the respective hammer and fire the respective barrel, said trigger having a blade with a projection, an auxiliary sear having arms in underlying relationship to the hammer sears, a shoulder structure connecting the arms and being adapted to sequester said projection, a spring tending to move the auxiliary sear into the sequestering position of said shoulder structure, a latch having a head obstructing the auxiliary sear and having a pin overlying the trigger blade for displacement upon said first pull, a pivot by which the latch is supported independently of the auxiliary sear, and a push block upon which the spring acts directly, said push block having a beveled face bearing against said shoulder structure.

7. In a fire arm, an auxiliary sear comprising a body having a shoulder structure at one end, said body having arms spaced apart and extending away from the shoulder structure, said shoulder structure thus provided a bridge between the arms, and upstanding abutments constituting the terminals of said arms.

8. In a fire arm, an auxiliary sear comprising a body including a bridge which constitutes a shoulder structure, said bridge having a projecting prong, said body having arms extending away from the bridge at the sides of said prong, and abutments constituting the terminals of said arms.

9. In a fire arm, an auxiliary sear comprising a body and a pair of arms, a bridge, being part of the body, establishing the spacing of the arms and defining a shoulder structure, a prong projecting from the bridge and separating the shoulders of said structure, and upturned portions at the terminals of said arms constituting abutments, the turns of said portions being rounded to serve as fulcrums for the auxiliary sear.

10. In a double-barreled fire arm having ham- Iners for the respective barrels, hammer sears to hold the hammers cooked, and a selected trigger to be intentionally pulled to actuate one hammer sear, release the respective hammer and fire the respective barrel, said trigger having a blade with a projection, an auxiliary sear in underlying relationship to the hammer sears and having a shoulder structure adapted to overlie the projection preparatory to a lever action by the auxiliary sear upon the second hammer sear when the selected trigger is given a second pull, a spring tending to move the auxiliary sear into the overlying position, a latch pivotally carried by the auxiliary sear, having a laterally extending head engaging behind a portion of the blade to restrain the auxiliary sear and having at least one lateral projection in line with the trigger projection for the displacement of the latter upon said first pull of the trigger, and a push block upon which the spring acts directly, said push block having a beveled face bearing against a portion of said shoulder structure, then moving said auxiliary sear to bring the shoulder structure into contact with the trigger projection to postpone the further movement of said auxiliary sear and permit said trigger to vibrate in an arc of idle motion the extent of which is defined by the height of the projection in reference to its contact with the shoulder structure, until said first trigger pull is voluntarily relaxed.

11. In a fire arm having a trigger plate, a movable push block having at least one bore and a counterbore, a push block mount carried by said plate, being recessed for the accommodation of the push block and having a fixed guide pin occupying the bore and counterbore and normally projecting beyond the push block, a spring seated between a wall of the recess and the base of the counterbore, the face of the push block adjacent to the opening of the counterbore being beveled and terminating in an apron which is abutta-ble with said mount.

12. In a fire arm having a trigger plate, triggers pivoted thereto, each trigger having a projection, said triggers having hammer sears correlated therewith, a single-trigger device comprising an auxiliary sear riding upon the plate and in floating relationship to the triggers, said auxiliary sear including a bridge defining shoulders, a latch to detain the auxiliary sear upon the first pull of a selected trigger and during the ensuing movement of the hammer sear and advancement of said projection into engagement with the respective shoulder, a pressure actuated push block exercising constant tension upon the bridge to keep the auxiliary sear in its riding relationship to the trigger plate, and at least one stationary pin upon which the push block is movably mounted, having its tip initially projected from the push block and overlying the bridge to keep the auxiliary sear from being lifted by said first trigger plate.

FREDERICK T. FAHLEN. 

